Re: Enabling acpicpu(4) by default

[Steven Bellovin <smb%cs.columbia.edu@localhost>]

On Dec 30, 2010, at 11:07 51AM, Jukka Ruohonen wrote:

> Hello.
> 
> I would like to enable acpicpu(4) in the i386 and amd64 GENERIC kernels.
> The following options(4) must be commented out for this:
> 
>       - INTEL_ONDEMAND_CLOCKMOD
>       - ENHANCED_SPEEDSTEP
>       - EST_FREQ_USERWRITE
>       - POWERNOW_K7
>       - POWERNOW_K8
> 
> As can be read from comments and CVS logs, the listed options are also
> increasingly difficult to maintain. From a maintenance point of view, the
> used linear interpolation was an improvement from the older table-based
> approach, but there are cases where this overestimates the frequencies and
> hence carries the risk of writing garbage values to the registers. Against
> this, acpicpu(4) can be seen as going back to the roots; most of the existing
> tables in "est.c" were actually collected from ACPI information.
> 
> Moreover, without acpicpu(4), NetBSD is not going to support such things as
> C-states, AMD processors newer than K8, CPU thermal management, or TurboBoost.
> No functionality will be lost, but the GENERIC kernels can not provide
> out-of-the-box experience for both Pentium III and Core i7.
> 
What about pkgsrc/sysutils/estd -- will that work with acpicpu?


                --Steve Bellovin, http://www.cs.columbia.edu/~smb